% Pygame % % Joe Naegele

http://pygame.org

• Background
• API
• Demo

Python library designed for writing games

• Written by Pete Shinners
• Can be used for more than just games
• Old and not very "Pythonic"

• Cross-platform
• Does not require OpenGL
• Runs on Android but not iOS

• Small codebase
• Easy to learn
• Simple to use

• Uses optimized C and assembly code for its core functions
• Significantly faster than pure Python code
• Relatively slower than most libraries/languages

Simple DirectMedia Layer

• Well-established (since 1998)

• Cross-platform C library

• Provides low-level access to hardware:

  • audio
  • graphics
  • keyboard, mouse, joystick

http://pyglet.org

• Built on OpenGL
• More "Pythonic" API
• Smaller community

http://kivy.org

• Young, modern, well-designed
• Much larger UI library, more than just games
• Runs on iOS

• Extensive but easy to use
• Slow but not too slow
• Great for prototyping!

You can make great games with Pygame!

• http://pygame.org/docs/
• Read the Newbie Guide
• "Learn" section of the website - books and tutorials

Pygame ships with a number of small examples

python -mpygame.examples.chimp

At a very basic level, we need the ability to:

• draw on the screen
• handle user input
• maybe play sounds

You must write the "main" loop

• manually process events
• update game logic
• render frame

Simplest approach: do it all in one loop

def main():
    while True:
        for event in events:
            handle(event)
        for entity in game:
            entity.update()
        for entity in game:
            entity.render()

Contrast this with Pyglet:

def main():
    win = pyglet.window.Window()

    @win.event
    def on_draw():
        win.clear()
        entity.render()

    def update(dt):
        entity.update()

    pyglet.clock.schedule_interval(update, 0.2)
    pyglet.app.run()

• http://pygame.org/docs

• pygame.init()

• pygame.display.init()
• pygame.display.set_mode(resolution, flags=0, ...)
• flags: FULLSCREEN, OPENGL, RESIZABLE, etc.
• pygame.display.update()
• python -mpygame.examples.glcube

• object for representing images, including display
• like a "blank piece of paper"
• pygame.Surface.blit - draw one image onto another
• pygame.Surface.fill - fill with solid color
• pygame.Surface.set_alpha - set transparency level
• python -mpygame.examples.scroll

• key presses
• mouse motion and clicks
• joystick manipulation
• window resize
• Event queue must be flushed continuously: for event in pygame.event.get(): ...
• python -mpygame.examples.eventlist

• pygame.sprite.Sprite
• pygame.sprite.Group
• pygame.sprite.collide_{rect, circle, mask}
• python -mpygame.examples.testsprite

• pygame.font.init
• pygame.font.Font(filename)
• python -mpygame.examples.fonty
• python -mpygame.examples.freetype_misc

• pygame.image.load(filename) -> Surface
• pygame.image.load(fileobj) -> Surface
• pygame.image.save(Surface, filename)
• python -mpygame.examples.moveit

• pygame.mixer.init(frequency, size, channels, buffer)
• pygame.mixer.Channel
• pygame.mixer.Sound
• python -mpygame.examples.sound

• pygame.time.wait (sleep)
• pygame.time.Clock

• "Rects are your friends"
• Lowly rectangle object
• Used by much of Pygame's API
• pygame.Rect(left, top, width, height)
• pygame.Rect((left, top), (width, height))
• etc.

(borrowed from the Newbie Guide)

Use surface.convert() after loading an image for up to 6x increase in blitting speed

background = pygame.image.load("background.png")
background.convert()

This changes the surface's pixel format to match that of the display

Only update "dirty" rects

pygame.display.update() updates the entire screen, which isn't always what you want

Pass a Rect or list of Rects to pygame.display.update()

• Not useful for things like side-scrollers
• Not needed for low-framerate games/apps

• Don't bother with per-pixel collision detection
• Python is too slow
• Just use "sub-rect" collision

2 methods of determining state...

1. Directly check state of the device:

   • pygame.key.get_pressed()
   • pygame.mouse.get_pressed()
   • pygame.mouse.get_pos()

2. Monitor event queue:

   for event in pygame.event.get():
       if event.type == ...

   • KEYDOWN, KEYUP
   • MOUSEMOTION, MOUSEBUTTONDOWN, MOUSEBUTTONUP

QANAT - Galaxians-like SHMUP

by Paul Patterson

SubTerrex

by Paul Patterson

Barbie Seahorse Adventures

by Phil Hassey

Ardentryst - RPG

by Jordan Trudgett

Frets on Fire - Guitar Hero clone

by Sami Kyöstilä

Void Infinity - Space RTS

by Jeremy Gagnier

• StarPusher - Puzzle game by Al Sweigart
• Ulmo's Adventure - Zelda-like adventure game by Sam Eldred
• SolarWolf - Arcade shooter
• Albow - GUI library by Gregory Ewing

• Doodle Jump
• FlapPy Bird
• Star Pusher
• The Stolen Crown
• Pacman Python
• Space Shooter

1. Import/Initialize
2. Load resources
3. Main loop
   • event loop
   • update
   • draw